that is made from them.  We stopped sometimes to examine a particularly large specimen, which might measure 30 feet round, and to see the juice, which had collected in the night, drawn out of the great hollow that had been cut to receive it, in the heart of the plant.  The Indians have a great fancy for making crosses, and the aloe lends itself particularly to this kind of decoration.  They have only to cut off six or eight inches of one leaf, and impale the piece on the sharp point of another, and the cross is made.  Every good-sized aloe has two or three of these primitive religious emblems upon it.

Several little torrent-beds crossed the road, and over them were thrown old-fashioned Spanish stone bridges, as steep as the Rialto, or the bridge on the willow-patterned plates.

Before going to see the pyramids, we visited the caves in the hill-side not far from them, whence the stone was brought to build them.  It is tetzontli, the porous amygdaloid which abounds among the porphyritic hills, a beautiful building-stone, easily worked, and durable.  There was a large space that seemed to have been quarried out bodily, and into this opened numerous caves.  We left our horses at the entrance, and spent an hour or two in hunting the place over.  The ground was covered with pieces of obsidian knives and arrow-heads, and fragments of what seemed to have been larger tools or weapons; and we found numbers of hammer-heads, large and small, mostly made of greenstone, some whole, but most broken.

We find two sorts of stone hammers in Europe.  Solid hammers belong to the earliest period.  They are made of longish rolled pebbles; some are shaped a little artificially, and are grooved round to hold the handle, which was a flexible twig bent double and with the two ends tied together, so as to keep the stone head in its place.  The hammers of a later period of the “stone age” are shaped more like the iron ones our smiths use at the present day, and they have a hole bored in the middle for the handle.  In Brittany, where Celtic remains are found in such abundance, it is not uncommon to see stone hammers of the latter kind hanging up in the cottages of the peasants, who use them to drive in nails with.  They have an odd way of providing them with handles, by sticking them tight upon branches of young trees, and when the branch has grown larger, and has thus rivetted itself tightly on both sides of the stone head, they cut it off, and carry home the hammer ready for use.

Though the Mexicans carried the arts of knife and arrow-making and sculpturing hard stone to such perfection, I do not think they ever discovered the art of making a hole in a stone hammer.  The handles of the axes shown in the picture-writings are clumsy sticks swelling into a large knob at one end, and the axe-blade is fixed into a hole in this knob.  Some of the Mexican hammers seem to have had their handles fixed in this way; while others were made with a groove, in the same manner as the earlier kind of European stone hammers just described.